A lawsuit by a civil liberties group seeks to force the US government to disclose its policies and contracts for facial recognition technology being deployed at airports around the United States

A civil liberties watchdog sued the US government Thursday seeking the disclosure of records on the use of facial recognition technology being deployed at American airports.

The American Civil Liberties Union said it was seeking to force the Department of Homeland Security to release records on its contracts and policies for the technology which has been expanded in recent months.

ACLU staff attorney Ashley Gorski said the lawsuit aims to require disclosure of what the government is doing with the data it collects with face-scanning machines.

The expanded deployment is "putting us on an extraordinarily dangerous path toward the normalization of face surveillance," Gorski said in a statement.

"But because key facts about this surveillance are still secret, the public lacks the information it needs to hold these agencies to account. We're suing to bring some much-needed transparency."

The ACLU said DHS and other have declined to respond to freedom of information requests on contracts with airlines, airports and other entities, and on retention policies regarding biometric information collected.

"The little we do know about the government's plans for face surveillance at airports is deeply disturbing," Gorski said.

ACLU said US officials have left open the possibility of mandating face surveillance on all US citizens traveling internationally and that non-citizens are currently unable to opt out of being subjected to the scans.

The lawsuit comes amid increased deployment—and complaints—about the use of facial recognition for and private applications.

Backers of facial recognition at airports say it can ease long lines and make it easier to catch suspected criminals. But civil liberties activists argue it may be used for intrusive of innocent people.

The ACLU last year sued the FBI to seek disclosure of its database believed to hold at least 640 million images and other biometric data.